Don't use a fixed size buffer for printed messages

2 files changed, 31 insertions, 24 deletions

diff --git a/Alc/helpers.cpp b/Alc/helpers.cpp
index 29b613cc..d9133842 100644
--- a/Alc/helpers.cpp
+++ b/Alc/helpers.cpp
@@ -358,13 +358,22 @@ void *GetSymbol(void *handle, const char *name)
 
 void al_print(const char *type, const char *prefix, const char *func, const char *fmt, ...)
 {
-    char str[1024];
-    va_list ap;
-
-    va_start(ap, fmt);
-    vsnprintf(str, sizeof(str), fmt, ap);
-    va_end(ap);
-    str[sizeof(str)-1] = 0;
+    al::vector<char> dynmsg;
+    char stcmsg[256];
+    char *str{stcmsg};
+
+    va_list args, args2;
+    va_start(args, fmt);
+    va_copy(args2, args);
+    int msglen{std::vsnprintf(str, sizeof(stcmsg), fmt, args)};
+    if(UNLIKELY(msglen >= 0 && static_cast<size_t>(msglen) >= sizeof(stcmsg)))
+    {
+        dynmsg.resize(static_cast<size_t>(msglen) + 1u);
+        str = dynmsg.data();
+        msglen = std::vsnprintf(str, dynmsg.size(), fmt, args2);
+    }
+    va_end(args2);
+    va_end(args);
 
     std::wstring wstr{utf8_to_wstr(str)};
     fprintf(gLogFile, "AL lib: %s %s%s: %ls", type, prefix, func, wstr.c_str());
diff --git a/OpenAL32/alError.cpp b/OpenAL32/alError.cpp
index a02d09c9..2c2a80eb 100644
--- a/OpenAL32/alError.cpp
+++ b/OpenAL32/alError.cpp
@@ -22,6 +22,7 @@
 
 #include <csignal>
 #include <cstdarg>
+#include <cstdio>
 
 #ifdef HAVE_WINDOWS_H
 #define WIN32_LEAN_AND_MEAN
@@ -36,28 +37,25 @@ ALboolean TrapALError = AL_FALSE;
 
 void alSetError(ALCcontext *context, ALenum errorCode, const char *msg, ...)
 {
-    char message[1024]{};
+    auto message = al::vector<char>(256);
 
-    va_list args;
+    va_list args, args2;
     va_start(args, msg);
-    int msglen{vsnprintf(message, sizeof(message), msg, args)};
-    va_end(args);
-
-    if(msglen < 0 || static_cast<size_t>(msglen) >= sizeof(message))
-    {
-        message[sizeof(message)-1] = 0;
-        msglen = static_cast<int>(strlen(message));
-    }
-    if(msglen > 0)
-        msg = message;
-    else
+    va_copy(args2, args);
+    int msglen{std::vsnprintf(message.data(), message.size(), msg, args)};
+    if(msglen >= 0 && static_cast<size_t>(msglen) >= message.size())
     {
-        msg = "<internal error constructing message>";
-        msglen = static_cast<int>(strlen(msg));
+        message.resize(static_cast<size_t>(msglen) + 1u);
+        msglen = std::vsnprintf(message.data(), message.size(), msg, args2);
     }
+    va_end(args2);
+    va_end(args);
+
+    if(msglen >= 0) msg = message.data();
+    else msg = "<internal error constructing message>";
+    msglen = static_cast<int>(strlen(msg));
 
-    WARN("Error generated on context %p, code 0x%04x, \"%s\"\n",
-         context, errorCode, message);
+    WARN("Error generated on context %p, code 0x%04x, \"%s\"\n", context, errorCode, msg);
     if(TrapALError)
     {
 #ifdef _WIN32